Ia is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of bat

Bat

Bats are mammals of the order Chiroptera "hand" and pteron "wing") whose forelimbs form webbed wings, making them the only mammals naturally capable of true and sustained flight. By contrast, other mammals said to fly, such as flying squirrels, gliding possums, and colugos, glide rather than fly,...

 in the family Vespertilionidae

Vesper bat

Vesper bats , also known as Evening bats or Common bats, are the largest and best-known family of bats. They belong to the suborder Microchiroptera . There are over three hundred species distributed all over the world, on every continent except Antarctica...

. It belongs to the subfamily Vespertilioninae

Vespertilioninae

Vespertilioninae is a subfamily of Vesper Bats from the family Vespertilionidae.-Classification:Subfamily Vespertilioninae*Tribe Eptesicini**Genus Arielulus***Collared Pipistrelle, Arielulus aureocollaris...

 and has been placed in the tribe Vespertilionini. In the past, it has also been considered a synonym

Synonym (taxonomy)

In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...

 or subgenus of the genera Pipistrellus

Pipistrellus

Pipistrellus is a genus of bats in the family Vespertilionidae and subfamily Vespertilioninae. The name of the genus is derived from the Italian word Pipistrello, meaning "bat"....

or Eptesicus

Eptesicus

Eptesicus is a genus of bats, commonly called house bats, in the family Vespertilionidae.The 25 species within this genus are:*Little black serotine *Bobrinski's Serotine...

, which used to contain many more species than they do now. Ia comprises a single living species, the great evening bat

Great Evening Bat

The great evening bat is a bat in the vesper bat family and the only living species in the genus Ia. It is common to Eastern and Southeastern Asia , mainly living in areas with limestone caves at altitudes of...

 (I. io) of eastern and southeastern Asia

Asia

Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

, and one extinct fossil

Fossil

Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

 species, I. lanna, from the Miocene

Miocene

The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...

 epoch in Thailand

Thailand

Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...

. Another living species, I. longimana, was recognized in the past, but it is no longer considered a valid species distinct from the great evening bat.

At two letters, Ia is the shortest possible name of any animal genus under the International Code of Zoological Nomenclature

International Code of Zoological Nomenclature

The International Code of Zoological Nomenclature is a widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals...

.